linux-kernel - Re: [PATCH v2 0/4] gpio: deprecate and track the removal of GPIO workarounds for regulators

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Message-ID: <CACRpkdaBNVyXUwErHTtGBnUjh4+6Ojb6fu9M4E7LnRCu_Oovpg@mail.gmail.com>
Date: Tue, 15 Apr 2025 23:32:57 +0200
From: Linus Walleij <linus.walleij@...aro.org>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: Mark Brown <broonie@...nel.org>, linux-gpio@...r.kernel.org, 
	linux-kernel@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH v2 0/4] gpio: deprecate and track the removal of GPIO
 workarounds for regulators

Hi Bartosz,

this caused me to think about a thing:

On Wed, Apr 2, 2025 at 12:05 PM Bartosz Golaszewski <brgl@...ev.pl> wrote:

> This is bothering me. This is the abstraction reversal I'm talking
> about. Should the regulator drivers even be concerned about whether
> they share resources or not?
(...)
> The part where "the higher level users want to understand that there
> is GPIO sharing going on" does not sound correct.

There are precedents for this type of semantic IRQF_SHARED
is used whenever two devices share the same IRQ line,
and that is something the drivers have to specify, i.e. the
driver has to be aware that it may be sharing the IRQ
with other devices, and whenever it gets an IRQ it has
to check "was it for me?" and in case it was, return
IRQ_HANDLED else IRQ_NONE.

Yours,
Linus Walleij